Iran crisis leaves Blair with few options

By Adrian Croft

LONDON (Reuters) - Britain has few alternatives to patient diplomacy as it tries to secure the release of 15 naval personnel held by Iran, with analysts all but ruling out use of force and sanctions widely seen as a slow, blunt weapon.

Iran's capture of the sailors and marines is a particularly unwelcome crisis for Prime Minister Tony Blair as he prepares to step down in the next few months after a decade in office, underlining the limits of British power.

Tehran accuses the Britons of illegally entering its waters. Britain says they were searching a ship in Iraqi waters.

"Apart from ... engaging in private negotiations and turning down the megaphone diplomacy, I don't think there's very much else you can do," said George Joffe, a Middle East specialist at Cambridge University's Centre of International Studies.

With its forces stretched to the limit in Iraq and Afghanistan, Britain has little scope to use military force.

"They could ask the Americans to intervene (but) the Americans would be simply mad if they did," Joffe said, pointing to the risk of Iranian-inspired retaliation in Iraq.

Any thought of launching a military mission to retrieve the British service personnel would anyway be tempered by memories of the failed 1980 U.S. commando mission to rescue 52 Americans held hostage for 444 days in the U.S. embassy in Tehran.

Political analysts say a European Union threat to restrict trade or export credit guarantees for Iran could be effective in the long run, but there is a question whether big trade powers such as Germany would put their interests at risk by using such a weapon.